Bylot Island

Bylot Island is part of Sirmilik National Park, on the northern coast of Baffin Island. It is a sanctuary for the largest Greater Snow Geese breeding colony in the Canadian Arctic. Through the years, biologists, limnologists and geomorphologists from the CEN network have established a research station in a lush valley on the south-western portion of the island. The island is partially glaciated and permafrost reaches depths of 400m. Members of the laboratory have been conducting research since the early 2000 on three particular projects: permafrost degradation by thermo-erosion, buried glacier ice paleo-climate reconstitution and fossil forest stratigraphic and paleo-environmental reconstitution.

Gullying created by thermo-erosion in ice-wedge polygon fields have been observed and monitored since 2001. The gullies are formed by melt water entering and running in frost-cracks during spring, convective heat exchanges and resultant massive ice degradation creating polygonal shaped gully networks. These gullies alter the hydrographic network and dry out nearby soils, therefore changing the vegetation cover.

 Massive buried ice bodies have recently been exposed by active-layer detachment slides. Early analyses have determined the ice is of a glacial origin, therefore containing precious information on past climatic conditions. The age of the oldest ice is estimated to be around 2.1 My, around the Pleistocene/Pliocène boundary, where massive glaciations were just beginning. The isotopic geochemistry will provide temperature data used for climatic reconstitutions of Bylot Island and northern Canada.

Permafrost is a great preserver of relics, and on Bylot Island a fossil forest was discovered buried under sediments and frozen into permafrost. Three trunks of a two meter length and up to 20cm in diameter, pine cones and roots have been unearthed, giving ample information for palynological and sedimentological analyses of the past environments. The fossil forest is suspected to date up to 2.5 My, during a warmer climate preceding the great Pleistocene glaciations.

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